Yeah, power being the last thing to go is probably the most inaccurate axiom in boxing. In many cases power is the FIRST thing to go, because guys lose their snap and velocity.
Agreed, most older fighters lose their power quite clearly. They usually get slower and fatter which is not a good blend for knocking fools out. Imo, the misconception probably is due to Foreman but he was far from the ''typical'' old boxer.
Ring craft is the last thing to go. Stuff that's based solely on experience never goes. This video from Lee Wylie shows Duran using his forearms to control which punches are his opponents' can and can't throw against Carlos Palomino, and again against Regis Prograis 50+ years later. Aside from stuff based in experience, no fighter should end their pro career weaker than they started. Physical strength can grow well past the age of a pro fighter set to retire, and in athletes especially.
